Twister spindle



March 19, 1957 J. V. KEITH TWISTER SPINDLE Filed Sept. 50, 1953 INVENTOR.

BY 'JOHN V KEITH A T TORN Y United States Patent TWISTER SPINDLE John V. Keith, Warwick, R. L, assignor to Universal Winding C0., Cranston, R. I., a corporation of Massachnsetts Application September 30, W53, Serial No. 383,263

Ill Claims. (Cl. 57-5836) The present invention relates to spindles for twisting yarn and more particularly relates to spindles of the multiple twist type.

In the following specification and claims the term yarn is employed in a general sense to apply to all kinds of strand materials, either textile or otherwise, and the designation package is intended to mean the precinct of a winding machine whatever its form.

Multiple twist spindles have been known to those skilled in the art for many years. Use of this type spindle, however, has not been wide-spread due to difticulties encountered in controlling the tension in the strand of yarn being twisted, in controlling the balloon formed by the rapidly rotating strand of yarn, and the fact that the yarn, carried by the spindle has a tendency to feed out of the twisting spindle when the running strand is broken. Accurate control of tension through a wide range of selection is necessary to accurately twist the great variety of yarns that a commercially successful spindle must be capable of twisting. The size and shape of the balloon formed by thetwisting yarn affects the tension in the strand of yarn and also. is the determining factor in the spacing of adjacent spindles. It is desirable to locate the spindles as close together as possible to obtain the greatest possible utilization of avail able space. When the supply of yarn continues to feed out of the spindle after it has broken, the end thereof is whipped around and becomes entangled. in adjacent yarn balloons causing those strands to break and; in addition.

the rapidly rotating end. beats against adjacent parts of the twisting machine and is broken into small fragments which fill the air in the room and contaminate yarn being processed within a wide area. A further disadvantage in prior multiple twist spindlcs is the possibility that the bearings supporting the normally stationary. supply of yarn being twisted may lock or seize with the result that said supply will be rotated at a very high speedto thereby cause the destruction of the spindle itself and the pos-.

sibility of severe physical injury. to the machine operator. It is, therefore, one. object of. the present invention to provide a multiple twist spindle having tension controlling means that are readily adjustable.

Another object of the present invention is to provide a multiple twist, spindle having a tension controlling means; capable of accurately controlling the tension of' a strand 0 of yarn being twisted through a wide range of tensions.

Another object; of-the present invention .is to provide a multiple twist spindle having a balloon restraininggnard adapted to move with the spindle asit moves hey tween its operative and inoperative positions.

Another object of the present invention is to providea t manner.

of yarn carried by the spindle in the event said strand breaks and to thereby prevent continued rotation of said spindle from feeding said yarn.

Another object of the present invention is to provide a multiple twist spindle with means to prevent the supply of yarn carried thereby from being discharged therefrom in the event the twisting operation is interrupted by breakage of the running strand.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the apparatus possessing the construction, combination of elements and arrangement of parts which are exemplified. in the following detailed disclosure, and the scope of the applica tion of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description takenin connection with the accompartying drawings wherein:

Pig. 1 is an elevation partly in section showing the multiple twist spindle of the present invention;

Fig. 2 is a fragmentary sectional view taken on the line Il.--1I of Fig. l and looking in the direction of the arrows;

Fig. 3 is a fragmentary sectional View taken on the line Illill of Fig. l and looking in the direction of the arrows;

Fig. 4 is a fragmentary sectional view taken on the line IV-IV of, Fig. 1 and looking in the direction. of the arrows;

Fig. 5 is an enlarged fragmentary view, partly in section, showing the yarn catching mechanism; and

Fig. 6 is a sectional view taken on the line VIVI of Fig. 5 and looking in the direction of the arrows.

Figure 1 shows a multiple twist spindle 10 carried. by a spindle swing. 14 of the type disclosed in, U. S. Patent 2,648,948, issued August 18, 1953, to D. G. Sousslotf et al. Spindle swing 14 includes a bracket portion 16, adapted to be secured to the bed of a twisting machine, having pivotally mounted thereon spindle carrying arm 18. Spindle 10 is resiliently secured in arm 18. by means of a vibration isolating mounting member 20 of the type disclosed in application for U. 8. Letters Patent Serial a whorl 22 fixed thereon, rotatably journaled in spindle. step 24 which. in turn is. secured in vibration isolating mounting 20. A conventional spindle driving belt, not

shown, is adapted to be engaged by whorl22 upon rear ward pivotal movement of arm 18 to thereby rotate said.

whorl and spindle blade 21 in an old and well known Forward pivotal movement of arm 18 disengages whorl 22 from the belt and brings said whorl into engagement with a fixed brake 28 to stop the rotation of the spindle and whorl. A disc like fiyer 30 is, fixedly secured to spindle 21 adjacent whorl 22 by means of key 31 and is provided with a radial passage 32. The inner end of passage 32 connects with an axial passage 34 provided in the upper end of spindle blade 21 to thereby form a passageway for the yarn being twisted. Wear resisting members 36 and 38 are provided in passage 32 t adjacent its outer endand at the juncture of said pas-.

multiple twist spindle having means to arrest the rotation of the yarn supply package carried thereby in the event the bearings supporting said supply package lock or seize, i

Another object. ofthe present invention is'to' provide a multiple twist spindle hayingjrnpans to catch the strandj sage 32 with axial passage 34 to resist abrasion by the. strand of yarn Y as it passes through said passages. The

periphery of fiyer 30 adjacent passage 34 comprises a yarn storage ring 33' adapted to receive a wrap or wraps.

of yarn when the spindle is in operation to assist in controlling the tension in yarn balloon, all in the manner familiar to those skilled in the art. Storage ring 33is slightly tapered, being of smaller diameter at its upper 3 edge than at its lower edge, so that when the spindle is operated with more than one wrap of yarn therearound the wraps will be spaced longitudinally and will not fall one upon the other. adjacent the upper edge of yarn storage ring 33 to guide the running strand of yarn around the upper portion of spindle as it leaves said storage ring.

A support for holding a supply of yarn to be twisted is mounted on spindle blade 21. Said support comprises a cylindrical member 46 journaled on the upper portion of spindle blade 21-bymeans of anti-friction bearings 48 and 50 which have their inner races in engagement with said spindle blade and their outer races located within resilient annular vibration isolating members 52 and 54 which in turn contact the inner surface of the lower end of cylindrical member 46. An annular upstanding ilange or rim 56 is carried by member 46 concentrically therewith by means of web portion 58 which connects the lower end of said member 46 and the lower end of flange 56. A permanent magnet 60 is fixedly secured in recess 80 in web 58, by any convenient means, as for example screw 62, and cooperates with a second permanent magnet 64 carried by upstanding arm 66 to prevent the rotation of said support member when spindle blade 21 is rotated. Magnet 64 is spaced from magnet 60 to provide a gap through which the yarn balloon can pass when the spindle is in operation. The lower end of arm 66 is secured, preferably by welding, to bracket member 6% which in turn is secured to spindle step 24 by having said step pass through a hole in one of its ends and being clamped between the lower end of vibration isolating mount 20 and the nut 70 which clamps said spindle step in said vibration isolating mount.

A second recess 72 is provided in the under side of web 58 diametrically opposite magnet 60. An L-shaped safety latch 74 is slidably journaled in said recess for radial movement in the same plane as magnet 64. Safety latch 74 is adapted to move, under the influence of magnet 64 from its normal inward position wherein its outer end is inside the circumference of web 58, to an outward position wherein its outer end will engage said magnet 64, in the event the yarn support starts to rotate with spindle blade 21 to prevent further rotation thereof. Latch 74 is normally held in its inward or withdrawn position by means of spring 76 having one of its ends in engagement with the upstanding portion of said latch and its other end in engagement with the opposed wall of recess 72. Latch 74 is retained in recess 72 by means of anannular cover plate 78 which encloses recesses 72 and 80 to-thereby present a smooth surface to the air currents set up by fiyer 30 as it rotates. A yarn supply carrying bobbin, comprising a cylindrical barrel 40, a flat circular head 42 secured to its lower end and a frusto-conical shaped upper head 44, of smaller diameter than head 42, secured to its upper end, fits over cylindrical member 46 and has its lower head supported by felt pad 82 on web58. A plurality of finger holes 45 are spaced around the tapering surface of frusto-conical head 44 to permit the bobbin and the supply of yarn carried thereby to be picked up by head 44 so that the lay of said yarn will. not be disturbed. A dome 84, preferably made of transparent plastic material, engages in a rabbet formed in the upper edge of flange 56 to enclose the bobbin, the supply of yarn carried thereby, and the tension mechanism to be explained hereinafter.

An adjustable yarn tensioning mechanism, see Figures 1, 2', ,3 and 4 is carried by cylindrical member 46. The tension device includes a magnet holding and yarn guiding tube 86 located within the bore of cylindrical member 46 and in alignment with axial passage 34 in spindle blade 21. Tube 86 is held against rotation in cylindrical member 46 by means of splines 88 formed on tube 86 slightly above its mid-point which fit into longitudinally extending grooves 90formed in said cylindrical member 46. One of the splines 88, and the groove with which Flyer 30 is provided with a flange 35 92 is such that its upper end extends beyond the upper 7 end of tube 86. v

An adjustable shunt 94 is positioned above circular magnet 92 and comprises a circular disc of magnetic material, such as iron, provided with a diametrically extending slot 96. Shunt 94 is mounted adjacent the upper end of tension cap 98. Tension cap 98 has a generally cylindrical lower portion located in the upper end of cylindrical member 46 and having a bore that surrounds magnet 92. its cylindrical portion joins a flange 108 thereon which rests upon the upper end of member 46 and its upper end 114 is frusto-conical in shape. A tension friction plate 100 is also carried by tension cap 98 immediately above shunt 94. Tension friction plate 100 is a disc provided with a central aperture 102 in alignment with the bore of tube 86 and is formed of a non-magnetic wear resistant material such as stainless steel, porcelain, etc. A tension disc 104 formed of magnetic material rests on tension friction plate 100 and is provided with a depending stem 106 loosely fitting in aperture 102 to permit the yarn Y drawn from the supply to pass between friction plate 100 and tension disc 104 and to pass through aperture 102 between the wall of said aper ture and depending stem 106 prior to travelling down tube 86, the axial passage 34 in spindle 21, and out radial passage 32 in flyer 30. Tension disc 104 is preferably formed fromthin material and depending stem 106 is preferably formed from a light weight plastic to reduce to a minimum the weight of said tension disc. Tension disc 104 is drawn against friction plate 100 by the circular magnet 92 tothereby apply a restraining or tension creating force to the strand of yarn being drawn between said plate and said disc. The magnetic force exerted on tension disc 104 can be adjusted to increase or decrease the force applied to the running strand of yarn by rotating shunt 94 relative to magnet 92 to cut off greater or less numbers of magnetic lines of force depending upon the position of slot 96 with respect to the poles of said magnet.. To facilitate this adjustment, and to insure the quick and accurate setting of the tension, tension cap 93 is rotatable within the upper end of cylindrical member 46 and is provided in the under side of its flange 106 With a plurality of holes 110 any one of which can fit over pin 112 upstanding from the upper end of said cylindrical member 46. 7

It will be understood that the maximum number of magnetic lines of force will pass through shunt 94 when the slot 96 formed therein is in alignment with the poles of magnet 92 and the minimum number of lines of force will pass through said shunt when said slot is at right angles to said magnetic poles. It will also be understood that there are two positions of said shunt when said slot therein is in alignment with said magnet poles, i. e. a first position, and a second position wherein said shunt is rotated degrees from the first position. In both of thesepositions of the shunt the maximum number of lines of force will pass therethrough. There are also twopositions of said shunt, 180 degrees apart, when the slot 96 is at right angles to the poles of magnet 92 and the same minimum number of lines of force will pass therethrough regardless of which position is used. It is also true that when shunt 94 is in an intermediate position, for example with its slot 96 forming an angle of 45 degrees to the poles of magnet 92, the same number of magnetic lines of force will pass through said shunt regardless of whether that 45 degree angle is made by saidslot being inclined from right to left or from left to right. In other words the efi'ect of shunt 94 depends upon the angle its slot makes with the poles of magnet 92 and the eifect is always the same regardless of whether the angle formed is right hand or left hand or is 180 degrees displaced. That being the case it is possible to calibrate tension cap 98 by using the entire 360 degrees of the surface of its flange 108 to give the effect of extremely small increments taken through 90 degrees of its circumference, and thus permit the holes 110 to be spaced four times as far apart as would be possible if the calibration were done in 90 degrees. Indicia consisting of letters of the alaphabet are stamped in the conical surface 114 of tension cap 98 with each letter corresponding to a hole 110. The hole 110 which, when engaged by pin 112, positions the slot in the shunt at 90 degrees to the magnet poles is given the letter A. Therefore when tension cap 98 is positioned so that pin 112 engages the hole marked A the minimum number of magnetic lines of force will pass through shunt 94 to draw tension disk 104 against tension friction plate 100, with the result that the minimum amount of tension will be applied to a strand of yarn drawn therebetween. The hole marked with the letter B is located in a clockwise direction, as viewed in Fig. 3, substantially 176 degrees from the hole A so that when tension cap 98 is rotated to the position wherein pin 112 engages hole B slot 96 will form an angle of 86 degrees with the poles of magnet 92. The hole marked with the letter C is located 12 degrees in a clockwise direction from the hole marked B and 188 degrees from the hole marked A. As a result when pin 112 is engaged in hole C slot 96 will form an angle of 82 degrees with the poles of magnet 92, but will be inclined in the opposite direction from its inclination when the hole B is engaged. The hole marked with the letter D is located 184 degrees in a clockwise direction, as viewed in Fig. 3, from the hole marked C and 12 degrees from the hole marked A. Therefore, when pin 112 is engaged in hole C slot 96 will form an angle of 78 degrees with the poles of mag net 92. The remaining holes 110 are located in the manner illustrated in Fig. 3 with. the result that moving tension cap 98 so that pin 112 engages holes 110 in alphabetical order, starting with the hole marked A, will vary the angle slot 96 makes with the poles of magnet 92 in increments of substantially 4 degrees.

Longitudinal grooves 116 are formed in the bore of cylindrical member 46 adjacent its upper end and cooperate with notches 118 in the upper edge of member 46 to provide a plurality of air passageways leading from the space surrounding the yarn supply package and the tension mechanism into the interior of cylindrical Inember 46. When flyer 30 is rotated at its high operational speed the radial passage 32 formed therein acts in the manner of a centrifugal pump and evacuates most of the air from the interior of cylindrical member 46. Notches 118 and longitudinal grooves 116 provide an air pas- 5 sage around tension disc 184 to permit the air enclosed by dome 84 to be drawn into the bore of cylindrical member 46 at the same rate said cylindrical member is evacuated, to maintain the pressure on both sides of tension disc 104 substantially equal. Failure to so vent the spindle would result in pressure outside cylindrical member 46 pressing tension disc 104 against friction plate 100 and result in excessive tension being applied to the strand of yarn being twisted.

In the event strand of yarn Y breaks after it has emerged from radial passage 32 in flyer 30, the centrifugal force exerted on the strand due to its rapid rotation by said flyer tends to draw yarn from the supply carried by the spindle. The rapid rotation of a free feeding strand of yarn causes the strand to strike adjacent parts of the twisting machine and break into small fragments that fill the air over a wide area to contaminate yarn being processed by other spindles and to clog bearings and gearing in all exposed mechanisms. The spindle of the present invention is provided with a device which per- 6 mits the free passage of the strand of yarn while the strand remains unbroken but which will, catch and hold it in the event it breaks. The yarn catching device 158 is disclosed in Figs. 1, 5 and 6 and includes a ring 160 threadedly secured to the lower end of yarn guiding tube 86. The bore of ring 160 is restricted to form a shoulder 162 which cooperates with the lower end of tube 86 to clamp yarn catching elements 164 and 166 to the end of said tube. Element 164 comprises a relatively rigid depending fiat finger 168 secured at its upper end to horizontal semi-circular member 170. The lower end of finger 168 is provided at each side thereof with a shallow flange or boss 172. Element 166 comprises a horizontal semi-circular member 174 having a downwardly inclined detent 176 formed thereon. A flat spring 178 has its upper end secured to detent 176 and forms a continuation thereof. The two semi-circular members and 174 when fitted together form a circle that will fit inside of ring 160 against the shoulder 162. Thus when said members 170 and 174 are fitted in ring 160 and said ring screwed on the lower end of tube 86 said members 170 and 174 are clamped between said tube and flange to thereby hold the lower end of flat spring 178 against fianges 172. Flanges 172 hold spring 178 spaced from finger 168 a distance slightly greater than the diameter of the strand of yarn Y to normally permit the free passage of said strand therebetween. When strand Y breaks the centrifugal force on said strand does not feed the strand as fast as it is normally drawn in the twisting process. As a result the length of yarn between fiyer 3t) and tension disc 104 is, in a very short time, twisted to such an extent that kinks are formed therein which can not pass through the space between finger 168 and spring 178 and the feeding of the strand is thus stopped. Continued rotation of flyer 30 after the strand Y has stopped will twist the strand to such an extent that it: will be twisted apart, usually just below the yarn catching device 158. After the strand has been twisted 011 on the axis of spindle blade 21 the flyer obviously can no longer exert any effect on the strand and any tendency for the strand to feed out of the spindle ceases. Spring 178 is flexible and is pushed aside by the threading needle employed to thread multiple twist spindles when said needle is passed down through tube 86. In the event it is desired to twist a yarn of different diameter on spindle 10 it is only necessary to replace finger 168 with another similar finger having flanges 172 thereon slightly higher than the diameter of the new strand of yarn.

A smooth ring 128 form-ed from .a wear resistant material is concentrically spaced around spindle 10 at approximately the point that would normally yield the maximum balloon diameter. Ring 12% is carried by upstanding arm 66 by means of mounting bracket 122 adjustably secured to said arm. Ring 120 functions to rest-rain the balloon formed by the rapidly rotating strand of yarn from being of excessive diameter thereby reducing the tension imposed on the strand of yarn due to centrifugal force and wind resistance .and also permitting sp ndles 10 to be spaced closer together. Inasmuch as ring 120 is carried by upstanding arm 66 which in turn is carried by spindle carrying arm 18 it will be seen that said ring will move with spindle 18 to and fnom its operative position and will always remain concentric therewith.

The above described apparatus operates in the following manner: After a bobbin of yarn has been placed over cylindrical member 46, tension disc 104 is removed and the strand of yarn Y from the supply is passed, by means of a conventional threading needle, through aperture 102 in friction pla-teltlil, slot 96 in magnetic shunt 94, yarn guiding tube 86, between finger 168 and spring 178 and through axial passage 34 of spindle blade 21, and out radial passage 32 in flyer 30. As the yarn emerges from radial passage 32 it is passed upwardly inside .of balloon restraining ring 120, through yarn guide, not shown, concentric with spindle blade 21, and onto any conven- 7 ient take-up. Tension disc 104 is then replaced on friction plate 100 with its depending stem 106 extending into aperture 102. Tension cap 98 is then lifted to free it from pin 112 and it is then rotated until the indicia marked thereon indicates that the desired setting of shunt 94 has been obtained, whereupon pin 112 is engaged in the appropriate hole 110 to insure that the setting will not change during the twisting operation. Following this, dome 84 is placed on annular flange 56 to enclose the yarn supply and tension mechanism, and arm. 13 is pivoted rearwardly to engage whorl 22 with the driving belt to place the spindle in operation. The yarn supply and tension mechanism is held against rotation by the magnets 60 and 64 so that rotation of fiyer 30 swings a loop of yarn about the supply, in the manner old and well known to those skilled in the art, to thereby insert two turns of twist into strand Y for every single rotation of said fiyer.

In the event bearings 48 and seize so that the yarn supply and its support start to rotate, L-shaped safety latch 74 will be drawn out of its recess 72 by ma gnct 64 as said latch approaches said magnet, whereupon the end portion of the latch will strike against side of the magnet and thereby prevent damage to the spindle which might take place if said yarn supply and its support were permitted to rotate at high speed.

in the event the strand of yarn being twisted breaks, rotation of fiyer 34) will import such a high degree of twist to the length of yarn between said flyer and tension disc 104 that kinks or snarls will be formed therein that can not pass between finger 16S and spring 173. Continued rotation of fiyer 3% will twist the strand :oif on :the axis of the spindle whereupon any tendency for the yarn to feed from the spindle will be ended.

Since certain changes may be made in the above apparatus without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not .in a limiting sense.

What is claimed is:

l. A device for tensioning yarn comprising a pair of juxtaposed friction plates adapted to engage a running strand of yarn passing therebetween to apply tension thereto, magnetic means for urging said plates together, and an adjustable shunt interposed between said magnetic means and said friction plates.

2. A device for tensioning yarn comprising a non-magnetic friction plate, a second friction plate formed from magnetic material in face-to-face relation to said nonmagnetic plate whereby a strand of yarn can be drawn therebetween, a magnet for urging said plates together, and an adjustable shunt interposed between said magnet and said friction plates.

3. A device for tensioning yarn comprising a non-magnetic friction plate, a second friction plate formed from magnetic material in face-to-face relation to said nonmagnetic plate whereby a strand of yarn can be drawn therebe-tween, a magnet positioned adjacent said non-n1agnetic plate in opposition to said second plate to draw said second plate against said non-magnetic plate, and adjustable shunt means interposed between said magnet and said non-magnetic plate.

4. A device for tensionin-g yarn comprising a pair of juxtaposed friction plates adapted to engage a running strand of yarn passing therebetween to apply tension thereto, a magnet for urging said plates together, and an adjustable shunt interposed between said magnet and said friction plates, said shunt comprising a rotatable member formed from magnetic material and having a slot extending therethrough, said shunt being rotatable from a position wherein said slot is substantially parallel with the poles of said magnet to a position wherein it is at substantially right angles thereto.

5. A device for tensioning yarn comprising a non-magnetic friction plate, a second friction plate formed from magnetic material in fac'e-to-fac e relation to said nonmagnetic plate whereby a strand of yarn can be drawn therebetween, a magnet positioned adjacent said non-magnetic plate in opposition to said second plate to draw said second plate against said non-magnetic plate, and adjustable shunt means interposed between said magnet and said non-magnetic plate, said shunt comprising a rotatable member formed from magnetic material and having a slot extending therethrough, said shunt being rotatable from a position wherein said slot is substantially parallel with the poles of said magnet tola position wherein it is at substantially right angles thereto.

6. A device for tensioning yarn comprising a friction. plate having an aperture therein for the passage of a strand of yarn, a second friction plate in face-to-face relation to said first mentioned friction plate whereby a strand of yarn can be drawn therebetween as it is drawn through said aperture, an annular magnet positioned adjacent said first mentioned plate and in alignment with said aperture to draw said second friction plate against said first mentioned friction plate, and an adjustable shunt interposed between said magnet and said first mentioned friction plate, said shunt comprising a member formed from magnetic material and having a slot extending t'ncrethrough in alignment with said aperture and the bore of said magnet, said shunt being rotatable from a position wherein said slot is substantially parallel with the poles of said magnet to a position wherein it is at substantially right angles thereto.

7. A multiple twist spindle comprising a rotatable spindle blade having an axial bore and a radial passage communicating therewith, a stationary yarn support including a cylindrical member coaxially mounted on said blade, an annular magnet mounted in said cylindrical member adjacent one end thereof, a tension cap adjustably carried by said cylindrical member adjacent said magnet, said tension cap including a friction plate having an aperture therein in alignment with the bore of said magnet and a magnetic shunt interposed between said magnet and said friction plate, and a tension disc in face-to-face relation to said friction plate and drawn thereagainst by said magnet, whereby a strand of yarn from a supply carried by said support can be drawn between said friction plate and said tension disc and through said aperture said bore and said radial passage, said shunt functioning to vary the force with which said tension disc is drawn against said friction plate in accordance with the adjusted position of said tension cap to thereby vary the tension imposed upon said strand of yarn.

8. A multiple twist spindle comprising a rotatable spindle blade having an axial bore and a radial passage communicating therewith, a stationary yarn support including a cylindrical member coaxially mounted on said blade, an annular magnet mounted in said cylindrical member adjacent one end thereof, a tension cap adjustably carried by said cylindrical member adjacent said magnet, said tension cap including a friction plate having an aperture therein in alignment with the bore of said magnet and a shunt comprising a member formed from magnetic material interposed between said magnet and said friction plate and having a slot extending therethrough in alignment with said aperture and the bore of said magnet, and a tension disc in face-to-face relation to said friction plate and drawn thereagainst by said magnet, whereby a strand of yarn from a supply carried by said support can be drawn between said friction plate and said tension disc and through said aperture, said slot, said bore and said radial passage, said shunt functioning to vary the force with which said disc is drawn against said friction plate as said tension cap is moved to vary the position of said slot with respect to the poles of said magnet.

9. A multiple twist spindle comprising a rotatable spindle blade havingan axial bore and-a radialpassage greases communicating therewith, a stationary yarn support including a cylindrical member coaxially mounted on said blade, an annular magnet having north and south poles mounted in said cylindrical member adjacent one end thereof, a tension cap carried by said cylindrical member adjacent said magnet and capable of being rotated manually relative to said magnet and said member, said tension cap including a friction plate having an aperture therein in alignment with the bore of said magnet and a shunt, said shunt comprising a member formed from magnetic material interposed between said magnet and said friction plate and having a slot extending therethrough in alignment with said aperture and the bore of said magnet, and a tension disc in face-to-face relation with said friction plate and drawn thereagainst by said magnet, whereby a strand of yarn from a supply carried by said support can be drawn between said friction plate and said tension disc and through said aperture, said slot, said bore and said radial passage, said shunt permitting a maximum number of magnetic lines of force to pass therethrough to act upon said tension disc when said slot is in substantial alignment with the poles of said magnet and permitting a minimum number to pass therethrough when said slot is at right angles to said poles, and means to permit incremental movement of said tension cap through 360 degrees to give the magnetic eifect upon said tension disc of incremented movement of said shunt through 90 degrees.

10. A multiple twist spindle comprising a rotatable spindle blade having an axial bore and a radial passage communicating therewith, a stationary yarn support including a cylindrical member coaxially mounted on said blade, an annular magnet having north and south poles mounted in said cylindrical member adjacent one end thereof, a tension cap carried by said cylindrical member adjacent said magnet and capable of being rotated manually relative to said magnet and said member, said tension cap including a friction disc having an axial aperture therein in alignment with the bore of said magnet and a shunt, said shunt comprising a disc like member formed from magnetic material interposed between said magnet and said friction plate and having a diametric slot extending therethrough, and a tension disc in faceto-face relation with said friction disc and drawn thereagainst by said magnet, whereby a strand of yarn from a supply carried by said support can be drawn between said friction plate and said tension disc and through said aperture, said slot, said bore and said radial passage, said shunt permitting a maximum number of magnetic lines of force to pass therethrough to act upon said tension disc when said slot is in substantial alignment with the poles of said magnet and permitting a minimum number to pass therethrough when said slot is at right angles to said poles, said tension cap having plurality of holes spaced around its full periphery, detent means on said cylindrical member for selectively engaging said holes whereby said tension cap and said shunt may be held against movement relative to said magnet.

References Cited in the file of this patent UNITED STATES PATENTS 2,445,721 Bartholomew July 20, 1948 2,473,521 Gwaltney June 21, 1949 2,478,926 Kingsbury Aug. 16, 1949 2,478,927 Carter Aug. 16, 1949 2,597,015 May May 20, 1952 2,614,773 Ammerall Oct. 21, 1952 2,620,617 Bley Dec. 9, 1952 2,662,364 Kingsbury Dec. 15, 1953 2,667,029 Uhlig Jan. 26, 1954 2,734,333 Griset et al. Feb. 14, 1956 

